Process of producing oxids of phosphorus and nitrogen compounds.



rrsn sures us sirnu r o' SAMUEL PEAGGCK, 9F GHICAGQ, ILLINOIS, ASSIGNGRTO Il'TER-NATIONAL AGEIGUL- TUE-AL tiGRE'QBATIUH, OF NEW Z'GRK. N. Y., ACQBEQMTION DF'NEW YQEX.

PROCESS 9F FREDUCING (2313313 (3?? PEGSFHOEUS ieND NITROGEN CQMEOUNDS.

To all whom it may concern Be it known that I, SAMUEL Pmcocn, a citizenof the United States, residing at- Chi cago, in the county of LookandState of Illinois, have invented certain new and use.- ful Improvementsin Processes of Producing ()Xids of Phosphorus and Nitrogen Qompounds;and i do hereby declare the following to he a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which .it oppertains to make and use the same. v

This invention relates to a process of separating phosphorus from itsphosphate combinations While at the same time producing carbids andnitrids of phosphorus which may be utilized-in the production-ofphosephorus oXids, or nitrogen suits at will.

The invention is dijided from my copending application No. 708,276, July8, 1912, entitled PITCESS of separating phosphorus from its phosphatecombinations and has for its object the attainment of the above resultsin a simple. expeditious and comparatively inexpensive manner, and tothese ends consists in the novel steps constituting my process all aswill bemore fully hereinafter disclosed and particularly pointed out inthe claim.

' In carrying out my process I finely divide a natural phosphate rocksuch as the tricolcium phosphate, Ca P O and mix same with a suitablequantity of finely divided -urbon such as ground coke, coal dust orother form of fuel carbon. The mixed carbon and phosphate is then heatedto a temperature of about 900 C. in an atmosphere containingsubstantially no free oxygen, when it is found that phosphorus isevolved either as a carbid such as 1 C, or in the form of a vapor. Ifthe reaction is carried out in anatmosphere of nitrogen, free from air,then phosphorus is given off as a nitrid, such as F ll or as acarho-nitrid such as P C N or as a mixture of these two compoundstogether with some carbid P 3 and a considerable quantity of freephosphorus, P, in a vaporous form At present em unable to say withcertainty whether this free phosphorus is displaced as suchoris adecomposition product. 'It is not probable,

Specification of Letters ?atent.

however, for various reasons, that free phosphorus would be producedunder the conditions stated, and therefore I believe its presonce is dueto a decomposition of one or more of the above compounds.

I llhile-phosohorus bearing compounds are produced at the temperatureand under the conditions stated, the velocity of the reaction is greatlyincreased by raising the tem erature\ to say between i100 and 130 C.Further, the decomposition of the phosphate is greatly facilitated bymaintaining a low partial pressure of the products of the reaction. Thismay be accomplished by carrying out the process in a gas tightfurnacethrough which the mixture is continuously Patented .Felo. 2s, leis.

H0 Drawing. original c arification flied July 8, 1912; Serial No.798.2%. Divided and this application filed August 1 1, 1913. fiertlnlNo. 784,837.

fed, while nitrogen'is admitted at thedizscharge end and continuouslydrawn through and out off-the furnace at the feed end; a vacuum pump atthe feed end of the furnace being used to maintain the partial pressuresat the desired values. But I prefer to maintain low partial pressures bysimply flushing the furnace continuously or at intervals during theprocess either with nitrogen, or with an inert or neutral gas such ashydrogen, carbon monoxid, or a mixture of'carbon, monoxid and nitrogenor even with ordinary fuel or illuminating gas.

p 1 am not. as yet able to say with certainty just who; atomic linkagesare involved in the products actually produced, but from the presence offree phosphorus, combinedcarbon and combined nitrogen (when nitrogen spresent in the furnace), and from dueto unexcess of nitrogen piesent,but I believe at least some of it as Well as sub substantially allof thefree phosphorus is due to secondary decompositions; hen the temperatureis high end he partial pressures hept low by flushing with nitrogencontain ng gas, most of the furnace products are found to be carbonmonoxid,

GO, and phosphorus carbo-nitrid P G N with'some free phosphorus andnitrogen as probable secondary d e-composition products.

It will be observed from the foregoing that at the comparatively lowtemperatures between 900 C. and 1300 0., I am enabled to ss arate outfrom its associated compoun s the phosphorus in phosphate rock,

- and to drive it oil in the form of a gas or produce the pentoxid, P 0which latter may then be recovered as such or combined with water in themanner well known, to form phosphoric acid, B 1 0 When the phosphorusnitrid, P N is present in sufiicient quantity to render the recovery ofits nitrogen profitable, this gas may be pumped from the furnace into anautoclave and treated with superheated steam at a pressure, of say notless than two atmospheres, when the following reaction takes place 2P N+24H,O= 6NH .H PO,+4NH 0n the other hand when the phosphoruscarbonitrid, P C N is present in suflicient quantity to render therecovery Of ltS combined nitrogen desirable,"it may be likewise pumpedinto an autoclave, and treated with superheated steam as abov' when thefollowing reaction will take-place:-

In treating the furnace gases with superheated steam, any phosphoruscarbid, P 6

that might be present will break up 01 Again, when it is desired toproduce phosphorus pent'oxid, P 0 only, instead of passing the furnacegases through fire clay tubes for-the recovery of free phosphorus I Iwith air in excess, and burned at once to the as above described, saidgases may' be mixed pentoxid form, when the latter may be recovered assuch, or treated with Water'to."

produce phosphoric acid, or with water and I bases to form phosphates inthe manner well known.

"In the step of treating the'furnace ases with superheated steam thevelocity 0 the reaction may be controlled by regulating the pressure ofthe steam. At two atmospheres pressure the reaction velocityis slow p asthe pressure andtherefore the tempera-' ture increases, however, thereaction velocity increases in accordance with well known thermodynamiclaws.

may vary the details of my process without departing from the spiritthereof, and

.' '70 It is obvious that thoseskilled in the art therefore, I do notwish to be limited to the above disclosure except as may be required bythe claim. I

-What I claim is:

e The process of producing oxide of phosphorus from natural phosphateswhich consists in heating a mixture oi a" phosphate and carbon in arratmosphere devoid of free oxygen toa temperature sufficient to bringabout the reaction; collecting the gases thus produced; and burning themwith an excess of air to produce the desired oxide, substantially asdescribed.

In testimony whereof I afiix my signa ture, in presence of twowitnesses.

' SAMUEL PEA'COCK.

Witnesses:

T. A. WITHERSPOON, Lee. H. Bnacxwoon.

